Benzoxazinoids (BXs) are indole-derived compounds in plants such as maize that may serve as chemical defenses against herbivores. They are stored as stable glucosides in plant cells and require the activity of glucosidases to release the corresponding toxic aglucones. Maize is commonly used in the feeding of ruminants. Yet, it is not clear what is the impact of the toxic compounds on the microbiome and the fate of BXs upon fermentation in the rumen. For this, in this project, we will elucidate the effect of BXs of maize on rumen fermentation characteristics and the microbiota in vitro using the rumen simulation technique (Rusitec).